Joining Date/Time with query in MS Access 2000

I am a Microsoft Access 2000 user and having a date/time problem. I have four separate date/time fields in a database which I am running queries through an ODBC link to the database. I need to join the STARTDATE and STARTTIME fields, and FINISHDATE and FINISHTIME fields in a query to be able to do manipulations with the dates.
The STARTDATE AND FINISHDATE fields show the “short date” format with time of 00:00:00, where the STARTTIME AND FINISHTIME fields show the dates 01-JAN-1899 with “long time” format.
How can I join the STARTDATE and STARTTIME with each other and the FINISHDATE and FINISHTIME with each other so that I only have two date/time combination fields?
I have used the concatenate way but then the query view the dates as string fields e.g.
Format(Left([STARTDATE],10,”Short Date”)) & “ “ & Format(Right([STARTTIME],11,”Long Time”))